Tunnel boring machine

Tunnel excavation and concreting

Our tunnel boring machine (TBM), cultom-built in Germany for the Montreal métro, was delivered to the Blue line project site in fall 2025. This massive rotary drilling machine will be used to dig and encase in concrete then tunnel linking the future Vertières station to the future Anjou station, a first in the Montreal metro system.

A real underground factory

With an impressive diameter of 9.7 metres, the TBM will both excavate the rock and build the tunnel walls over a distance of 4.6 kilometres, at a depth ranging from 18 to 40 meters.



Rotating head: The front of the TBM is a large wheel with cutting discs or cutting tools. It spins to destroy the rock or soil by breaking it up. 

Extraction of materials: Excavated materials are transported to the rear of the machine via a screw conveyor or auger. This material will then be removed from the tunnel by conveyor belts. 

Tunnel lining: Just behind the cutting head, the tunnel boring machine installs voussoirs (pre-cast concrete segments) to form the lining of the tunnel. This immediately stabilizes the walls and allows the tunnel work to continue safely. 

Progression underground: The tunnel boring machine moves forward thanks to hydraulic cylinders that rest on the already installed liner. It pushes the cutting head forward as it continues to drill. 
Guidance and control systems: Sensors and GPS systems can accurately track the path of the tunnel.  The crew in the operating cabin controls the speed, pressure, and cut parameters.

Technical specifications

  • Length: over 135 meters
  • Weight: over 2,000 tons
  • Distance to be covered: 4.6 kilometers
  • Excavation speed: Average rate of 10 to 15 meters per day
  • Number of segments to be installed: over 14,300 precast concrete segments

Yes, at each station along the way, since the transept is excavated in the open. 

The former Saint-Michel quarry, located very close to the construction site. The rock will belong to the City of Montreal, which will be able to reuse it for future developments. 

Unfortunately, no. Each tunnel boring machine is custom designed with very specific technical specifications for a given project. In some cases certain components can be reused for other projects. It should also be noted that the successful bidder (MBH) owns the machine and not the STM.

What will the tunnel boring machine’s name be? 

Stay tuned for the annoucement of the TBM's godmother, coming in May 2026.

 

A contest was held to name the tunnel boring machine (TBM) that will excavate and concrete the tunnel between Vertières and Anjou stations. This initiative aims to strengthen the bond between this major project and the communities it will serve.

Naming a TBM is a longstanding tradition in major infrastructure projects worldwide. According to this custom, the machine is symbolically placed under the protection of a godmother before it starts digging.

The process

Last January, we launched a call for proposals among our employees and partners to gather suggestions of living Québec women who have made significant contributions to fields related to this project, such as engineering, sustainable development or public transit.

A jury selected five finalists based on various criteria, including relevance, alignment with the project’s values and the impact of the candidate’s work. In addition to lending her name to the TBM, the chosen godmother will have the opportunity to follow the project’s progress and visit the crews on site. The public had the opportunity to choose their favourite godmother. The results will be announced in the coming weeks. 

Cast your vote

The voting period for your favourite godmother has now ended. 

To thank you for helping to choose the tunnel boring machine’s godmother, three people will be drawn at random to get the chance to attend the machine’s launch event, where the winning name will be revealed. The event will take place in spring 2026.

Will the tunnel boring machine be named Florence, Geneviève, Lisette, Louise or Michèle? Learn about the inspiring journey of the five finalists.

Florence Junca-Adenot
Transportation and Urban Planning Specialist


“If an event highlights the usefulness of public transport, I’m there! It’s an exciting project that stimulates the development of accessible neighbourhoods that are great places to live, moving us away from the prevailing gloom.”

Florence Junca-Adenot holds a doctorate in economics, a master’s degree in sociology from the University of Bordeaux, an MBA from Université Laval. She is associate professor in the Department of Urban and Tourism Studies (UQAM).

She launched her career in 1971 and has held various positions at UQAM, spearheading, among other things, the construction of the 10 phases of development of the UQAM campus in the heart of Montreal. At the same time, she has been active in her community, becoming Boucherville’s first female municipal councillor in 1978.

From 1990 to 1997 she chaired the organization tasked to revive Vieux Montréal, which led to the creation of the Pointe-à-Calière museum and the renovation of Marché Bonsecours.

From 1996 to 2004 she was Chief Executive Officer of the new Agence métropolitaine de transport (AMT). She was tasked with stimulating the revival of public transit in the metropolitan area, and she revived commuter trains and led the development of the metro to Laval.

Florence Junca-Adenot is a Knight of the Ordre national du Québec, a Commander of the Ordre de Montréal and an honorary doctorate from Université de Montréal. She has founded or led some 15 organizations and is still actively involved in urban planning and public transportation.

Geneviève Boisjoly
Transportation Planning Specialist Engineer

“I am honoured to have been selected among the finalists to become the tunnel boring machine’s godmother. I share this recognition with the entire Polytechnique community committed to advancing sustainable mobility.”

Geneviève Boisjoly is a professor at Polytechnique Montréal, where she specializes in transportation planning and sustainable mobility. She holds a bachelor’s degree in mechanical engineering from Polytechnique Montréal, a master’s degree in sustainability science from Lund University in Sweden and a PhD in urban planning from McGill University.

Her work focuses on the connections between transportation, travel habits and quality of life. Her research highlights the importance of social dimensions in transportation engineering—an aspect that remains underrepresented in traditional approaches. She also addresses issues of equity to better meet the needs of communities. 

Together with her team, she helps envision cities that are more accessible and better equipped to meet today’s mobility challenges.

Geneviève Boisjoly is a member of the Interuniversity Research Centre on Enterprise Networks, Logistics, and Transportation (CIRRELT) and of Institut de valorisation des données (IVADO).

Lisette St Onge
First female métro operator in Montréal

I loved my job as a métro operator. I never thought I would have the opportunity to become the godmother of the tunnel boring machine for the Blue line extension. “

In 1980, Lisette St Onge (then known as Lisette Renaud), was hired as a bus driver for the Commission de transport de la Communauté urbaine de Montréal (CTCUM, now STM). At that time, there were barely fifteen women behind the wheel, with the first female driver having been hired three years earlier.  

A few months later, Lisette learned that the métro network was looking for new operators. Intrigued, she applied and was accepted. Emboldened by her colleagues, she became Montréal’s first female métro operator in the spring of 1981.

It took more than six years before a second woman took the plunge and became an operator. Lisette benefited from a supportive work environment with kind, respectful colleagues who welcomed her warmly. 

Now retired, she has fond memories of her career, particularly having represented women in non-traditional occupations at the STM in various forum. 

Louise Millette
Driven engineer and professor

“Access to public transit is so important to me and to Montréal’s urban life. I would love to take part in something as significant as the Blue line extension.”

After graduating from Polytechnique Montréal with a bachelor’s degree in civil engineering, Louise Millette’s interests quickly focused on the environment and sustainable development. She then pursued a master’s degree in civil engineering at the University of British Columbia, then returned to Polytechnique Montréal for her PhD.

From 1990 to 2002, she worked at Bell Canada, playing a key role in identifying, developing and implementing strategies and programs for managing the company’s environmental aspects.

In 2001, she was appointed as director of Polytechnique Montréal’s Département des génies civil, géologique et des mines [Department of Civil, Geological and Mining Engineering]. She became the first woman to head one of this institution’s departments. In addition to her leadership role, she was committed to building a culture of sustainable development. Thanks to her drive, Polytechnique Montréal obtained several certifications and, in 2013, created the Bureau du développement durable [Sustainable Development Office].

A Knight of the Ordre de Montréal, Louise Millette is currently president of the Fondation Rivières. She has also served as chair of the board of the Ordre des ingénieurs du Québec and the Association québécoise de vérification environnementale, in addition her involvement in a number of other organizations.

Michèle Thibodeau-DeGuire
Engineer and Board Member

“As a civil engineer, I am honoured and deeply moved by this nomination. It would be a joy to take part in such an engaging project with deep roots in the community.”

In 1963, Michèle Thibodeau-DeGuire was the first woman to graduate with a degree in civil engineering from Polytechnique Montréal. She began her career as a structural engineer at Lalonde Girouard Letendre, and later became the first female consulting engineer in Quebec. From 1982 to 1984, she was Quebec’s delegate general in Boston, becoming the first woman to serve as Quebec’s delegate general abroad.

She joined Polytechnique Montréal in 1985, first as assistant to the president and then as director of public relations at the institution. From 1991 to 2012, she was president and CEO of Centraide of Greater Montreal, which enjoyed unprecedented success during her tenure. From 2013 to 2020, she was the first woman to hold the position of Chair of the Board of Directors of Polytechnique de Montréal.

As a Member of the Order of Canada, Knight of the National Order of Quebec and Commander of the Order of Montreal, Michèle Thibodeau-DeGuire has received countless distinctions over the years, including honorary 

Contest rules in PDF (in French only)

Contenu de l'onglet 3

Contenu de l'onglet 4

Contenu de l'onglet 5

The projet in images


The blue line extension project follows in the wake of the Déclaration du gouvernement du Québec et de la Ville de Montréal to revitalize Montréal East. Many projects are underway to give a new impetus to this sector. Increased mobility, economic development, and improved living environments are at the heart of this ambitious project. For more information, see Québec.ca/RevitalisationEstMontreal(in French only).